Here is additional information that might be helpful in diagnosing my problem: ubuntu@ubuntu:~$ sudo wvdialconf Editing `/etc/wvdial.conf'. Scanning your serial ports for a modem. Modem Port Scan<*1>: S0 S1 S2 S3 WvModem<*1>: Cannot get information for serial port. ttySL0<*1>: ATQ0 V1 E1 -- OK ttySL0<*1>: ATQ0 V1 E1 Z -- OK ttySL0<*1>: ATQ0 V1 E1 S0=0 -- OK ttySL0<*1>: ATQ0 V1 E1 S0=0 &C1 -- OK ttySL0<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 -- OK ttySL0<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK ttySL0<*1>: Modem Identifier: ATI -- SmartLink Soft Modem ttySL0<*1>: Speed 4800: AT -- OK ttySL0<*1>: Speed 9600: AT -- OK ttySL0<*1>: Speed 19200: AT -- OK ttySL0<*1>: Speed 38400: AT -- OK ttySL0<*1>: Speed 57600: AT -- OK ttySL0<*1>: Speed 115200: AT -- OK ttySL0<*1>: Speed 230400: AT -- OK ttySL0<*1>: Speed 460800: AT -- OK ttySL0<*1>: Max speed is 460800; that should be safe. ttySL0<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK Found a modem on /dev/ttySL0. Modem configuration written to /etc/wvdial.conf. ttySL0<Info>: Speed 460800; init "ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0"